A conventional saddle device disclosed in U.S. Pat. No. 694,875 includes a bottom seat, a shaft rod mounted to the bottom seat, and two saddles threadedly connected to the shaft rod. Each of the saddles has a front end portion, and a rear end portion opposite to the front end portion, and disposed for mounting the shaft rod. Two ends of the shaft rod respectively have a right-handed thread section and a left-handed thread section. The saddles are respectively and threadedly connected to the right-handed thread section and the left-handed thread section of the shaft rod.
When the shaft rod rotates, the right-handed thread section and the left-handed thread section cooperate to drive a relative movement between the saddles for adjusting a distance between the saddles.
Even if the conventional saddle device can adjust the distance between the saddles, for most of bicycles, a portion of a bicycle for mounting the saddles is fixed such that, the positions of the saddles in a front-rear direction are not adjustable for different users.
In addition, a user usually requires some repair tools and repair members for repairing the bicycle, and usually needs to bring a wallet, since the structure of the bicycle frame is simple, it is difficult to mount a bag on a bicycle frame near a saddle portion of the bicycle for receiving the repair tools, the repair members and the wallet.
Moreover, the conventional saddle device disclosed in U.S. Pat. No. 694,875 does not include a coupling structure for mounting a saddle bag, and a backrest structure for supporting the back of the user.